Merge tag 'objtool-urgent-2025-04-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool fixes from Ingo Molnar:
 "These are objtool fixes and updates by Josh Poimboeuf, centered around
  the fallout from the new CONFIG_OBJTOOL_WERROR=y feature, which,
  despite its default-off nature, increased the profile/impact of
  objtool warnings:

   - Improve error handling and the presentation of warnings/errors

   - Revert the new summary warning line that some test-bot tools
     interpreted as new regressions

   - Fix a number of objtool warnings in various drivers, core kernel
     code and architecture code. About half of them are potential
     problems related to out-of-bounds accesses or potential undefined
     behavior, the other half are additional objtool annotations

   - Update objtool to latest (known) compiler quirks and objtool bugs
     triggered by compiler code generation

   - Misc fixes"

* tag 'objtool-urgent-2025-04-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  objtool/loongarch: Add unwind hints in prepare_frametrace()
  rcu-tasks: Always inline rcu_irq_work_resched()
  context_tracking: Always inline ct_{nmi,irq}_{enter,exit}()
  sched/smt: Always inline sched_smt_active()
  objtool: Fix verbose disassembly if CROSS_COMPILE isn't set
  objtool: Change "warning:" to "error: " for fatal errors
  objtool: Always fail on fatal errors
  Revert "objtool: Increase per-function WARN_FUNC() rate limit"
  objtool: Append "()" to function name in "unexpected end of section" warning
  objtool: Ignore end-of-section jumps for KCOV/GCOV
  objtool: Silence more KCOV warnings, part 2
  objtool, drm/vmwgfx: Don't ignore vmw_send_msg() for ORC
  objtool: Fix STACK_FRAME_NON_STANDARD for cold subfunctions
  objtool: Fix segfault in ignore_unreachable_insn()
  objtool: Fix NULL printf() '%s' argument in builtin-check.c:save_argv()
  objtool, lkdtm: Obfuscate the do_nothing() pointer
  objtool, regulator: rk808: Remove potential undefined behavior in rk806_set_mode_dcdc()
  objtool, ASoC: codecs: wcd934x: Remove potential undefined behavior in wcd934x_slim_irq_handler()
  objtool, Input: cyapa - Remove undefined behavior in cyapa_update_fw_store()
  objtool, panic: Disable SMAP in __stack_chk_fail()
  ...

5 files changed, 28 insertions, 53 deletions

diff --git a/tools/objtool/arch/loongarch/decode.c b/tools/objtool/arch/loongarch/decode.c
index 02e490555966..b6fdc68053cc 100644
--- a/tools/objtool/arch/loongarch/decode.c
+++ b/tools/objtool/arch/loongarch/decode.c
@@ -63,7 +63,7 @@ static bool is_loongarch(const struct elf *elf)
 	if (elf->ehdr.e_machine == EM_LOONGARCH)
 		return true;
 
-	WARN("unexpected ELF machine type %d", elf->ehdr.e_machine);
+	ERROR("unexpected ELF machine type %d", elf->ehdr.e_machine);
 	return false;
 }
 
@@ -327,8 +327,10 @@ const char *arch_nop_insn(int len)
 {
 	static u32 nop;
 
-	if (len != LOONGARCH_INSN_SIZE)
-		WARN("invalid NOP size: %d\n", len);
+	if (len != LOONGARCH_INSN_SIZE) {
+		ERROR("invalid NOP size: %d\n", len);
+		return NULL;
+	}
 
 	nop = LOONGARCH_INSN_NOP;
 
@@ -339,8 +341,10 @@ const char *arch_ret_insn(int len)
 {
 	static u32 ret;
 
-	if (len != LOONGARCH_INSN_SIZE)
-		WARN("invalid RET size: %d\n", len);
+	if (len != LOONGARCH_INSN_SIZE) {
+		ERROR("invalid RET size: %d\n", len);
+		return NULL;
+	}
 
 	emit_jirl((union loongarch_instruction *)&ret, LOONGARCH_GPR_RA, LOONGARCH_GPR_ZERO, 0);
 
diff --git a/tools/objtool/arch/loongarch/orc.c b/tools/objtool/arch/loongarch/orc.c
index 873536d009d9..b58c5ff443c9 100644
--- a/tools/objtool/arch/loongarch/orc.c
+++ b/tools/objtool/arch/loongarch/orc.c
@@ -41,7 +41,7 @@ int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruct
 		orc->type = ORC_TYPE_REGS_PARTIAL;
 		break;
 	default:
-		WARN_INSN(insn, "unknown unwind hint type %d", cfi->type);
+		ERROR_INSN(insn, "unknown unwind hint type %d", cfi->type);
 		return -1;
 	}
 
@@ -55,7 +55,7 @@ int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruct
 		orc->sp_reg = ORC_REG_FP;
 		break;
 	default:
-		WARN_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base);
+		ERROR_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base);
 		return -1;
 	}
 
@@ -72,7 +72,7 @@ int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruct
 		orc->fp_reg = ORC_REG_FP;
 		break;
 	default:
-		WARN_INSN(insn, "unknown FP base reg %d", fp->base);
+		ERROR_INSN(insn, "unknown FP base reg %d", fp->base);
 		return -1;
 	}
 
@@ -89,7 +89,7 @@ int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruct
 		orc->ra_reg = ORC_REG_FP;
 		break;
 	default:
-		WARN_INSN(insn, "unknown RA base reg %d", ra->base);
+		ERROR_INSN(insn, "unknown RA base reg %d", ra->base);
 		return -1;
 	}
 
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index 7567c893f45e..33d861c04ebd 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -36,7 +36,7 @@ static int is_x86_64(const struct elf *elf)
 	case EM_386:
 		return 0;
 	default:
-		WARN("unexpected ELF machine type %d", elf->ehdr.e_machine);
+		ERROR("unexpected ELF machine type %d", elf->ehdr.e_machine);
 		return -1;
 	}
 }
@@ -173,7 +173,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 	ret = insn_decode(&ins, sec->data->d_buf + offset, maxlen,
 			  x86_64 ? INSN_MODE_64 : INSN_MODE_32);
 	if (ret < 0) {
-		WARN("can't decode instruction at %s:0x%lx", sec->name, offset);
+		ERROR("can't decode instruction at %s:0x%lx", sec->name, offset);
 		return -1;
 	}
 
@@ -321,7 +321,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 			break;
 
 		default:
-			/* WARN ? */
+			/* ERROR ? */
 			break;
 		}
 
@@ -561,8 +561,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 			if (ins.prefixes.nbytes == 1 &&
 			    ins.prefixes.bytes[0] == 0xf2) {
 				/* ENQCMD cannot be used in the kernel. */
-				WARN("ENQCMD instruction at %s:%lx", sec->name,
-				     offset);
+				WARN("ENQCMD instruction at %s:%lx", sec->name, offset);
 			}
 
 		} else if (op2 == 0xa0 || op2 == 0xa8) {
@@ -646,7 +645,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
 			if (disp->sym->type == STT_SECTION)
 				func = find_symbol_by_offset(disp->sym->sec, reloc_addend(disp));
 			if (!func) {
-				WARN("no func for pv_ops[]");
+				ERROR("no func for pv_ops[]");
 				return -1;
 			}
 
@@ -776,7 +775,7 @@ const char *arch_nop_insn(int len)
 	};
 
 	if (len < 1 || len > 5) {
-		WARN("invalid NOP size: %d\n", len);
+		ERROR("invalid NOP size: %d\n", len);
 		return NULL;
 	}
 
@@ -796,7 +795,7 @@ const char *arch_ret_insn(int len)
 	};
 
 	if (len < 1 || len > 5) {
-		WARN("invalid RET size: %d\n", len);
+		ERROR("invalid RET size: %d\n", len);
 		return NULL;
 	}
 
diff --git a/tools/objtool/arch/x86/orc.c b/tools/objtool/arch/x86/orc.c
index b6cd943e87f9..7176b9ec5b05 100644
--- a/tools/objtool/arch/x86/orc.c
+++ b/tools/objtool/arch/x86/orc.c
@@ -40,7 +40,7 @@ int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruct
 		orc->type = ORC_TYPE_REGS_PARTIAL;
 		break;
 	default:
-		WARN_INSN(insn, "unknown unwind hint type %d", cfi->type);
+		ERROR_INSN(insn, "unknown unwind hint type %d", cfi->type);
 		return -1;
 	}
 
@@ -72,7 +72,7 @@ int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruct
 		orc->sp_reg = ORC_REG_DX;
 		break;
 	default:
-		WARN_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base);
+		ERROR_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base);
 		return -1;
 	}
 
@@ -87,7 +87,7 @@ int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruct
 		orc->bp_reg = ORC_REG_BP;
 		break;
 	default:
-		WARN_INSN(insn, "unknown BP base reg %d", bp->base);
+		ERROR_INSN(insn, "unknown BP base reg %d", bp->base);
 		return -1;
 	}
 
diff --git a/tools/objtool/arch/x86/special.c b/tools/objtool/arch/x86/special.c
index 9c1c9df09aaa..403e587676f1 100644
--- a/tools/objtool/arch/x86/special.c
+++ b/tools/objtool/arch/x86/special.c
@@ -3,11 +3,9 @@
 
 #include <objtool/special.h>
 #include <objtool/builtin.h>
+#include <objtool/warn.h>
 
-#define X86_FEATURE_POPCNT (4 * 32 + 23)
-#define X86_FEATURE_SMAP   (9 * 32 + 20)
-
-void arch_handle_alternative(unsigned short feature, struct special_alt *alt)
+void arch_handle_alternative(struct special_alt *alt)
 {
 	static struct special_alt *group, *prev;
 
@@ -31,34 +29,6 @@ void arch_handle_alternative(unsigned short feature, struct special_alt *alt)
 	} else group = alt;
 
 	prev = alt;
-
-	switch (feature) {
-	case X86_FEATURE_SMAP:
-		/*
-		 * If UACCESS validation is enabled; force that alternative;
-		 * otherwise force it the other way.
-		 *
-		 * What we want to avoid is having both the original and the
-		 * alternative code flow at the same time, in that case we can
-		 * find paths that see the STAC but take the NOP instead of
-		 * CLAC and the other way around.
-		 */
-		if (opts.uaccess)
-			alt->skip_orig = true;
-		else
-			alt->skip_alt = true;
-		break;
-	case X86_FEATURE_POPCNT:
-		/*
-		 * It has been requested that we don't validate the !POPCNT
-		 * feature path which is a "very very small percentage of
-		 * machines".
-		 */
-		alt->skip_orig = true;
-		break;
-	default:
-		break;
-	}
 }
 
 bool arch_support_alt_relocation(struct special_alt *special_alt,
@@ -156,8 +126,10 @@ struct reloc *arch_find_switch_table(struct objtool_file *file,
 	 * indicates a rare GCC quirk/bug which can leave dead
 	 * code behind.
 	 */
-	if (reloc_type(text_reloc) == R_X86_64_PC32)
+	if (reloc_type(text_reloc) == R_X86_64_PC32) {
+		WARN_INSN(insn, "ignoring unreachables due to jump table quirk");
 		file->ignore_unreachables = true;
+	}
 
 	*table_size = 0;
 	return rodata_reloc;